99979994 has 16 divisors (see below), whose sum is σ = 159337800. Its totient is φ = 46960704.

The previous prime is 99979993. The next prime is 99980003. The reversal of 99979994 is 49997999.

It can be written as a sum of positive squares in 4 ways, for example, as 83046769 + 16933225 = 9113^2 + 4115^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 99979994.

It is not an unprimeable number, because it can be changed into a prime (99979993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21149 + ... + 25440.

Almost surely, 2^99979994 is an apocalyptic number.

99979994 is a deficient number, since it is larger than the sum of its proper divisors (59357806).

99979994 is a wasteful number, since it uses less digits than its factorization.

99979994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46657.

The product of its digits is 14880348, while the sum is 65.

The square root of 99979994 is about 9998.9996499650. Note that the first 3 decimals coincide. The cubic root of 99979994 is about 464.1279280881.

It can be divided in two parts, 9997 and 9994, that added together give a palindrome (19991).

The spelling of 99979994 in words is "ninety-nine million, nine hundred seventy-nine thousand, nine hundred ninety-four".